1. Field of the Invention
The present invention relates to a lane departure warning device and method of a vehicle, and more particularly, to a technology of limiting lane departure warnings in a special road environment in a case where it is confirmed that a driver has a lane departure intention, and so on.
2. Description of the Prior Art
An electric power steering apparatus of a vehicle includes a torque sensor configured to sense the torque of a steering shaft connected to a steering wheel, an electric motor linked with a steering output shaft or a rack bar to rotate/move the steering output shaft or the rack bar, a steering ECU configured to control the rotation of the electric motor according to a steering torque value measured by the torque sensor, and so on.
The electric power steering apparatus basically performs an operation of generating a steering assist current to be proportional to the steering torque according to a driver's operation of the steering wheel so as to rotate the electric motor. That is, the electric power steering apparatus performs a basic operation for assisting the user's steering force.
However, according to the development of a Driving Assistance System (DAS) and a demand for autonomous traveling or the like, an autonomous steering control or an active steering control has been recently developed which automatically operates the electric power steering system regardless of the user's intention, in addition to a basic function of simply assisting the driver's steering force.
According to the autonomous steering control or the active steering control, there are various control systems related to steering, which affect the electric power steering system of a vehicle.
An example of the control system related to the steering of a vehicle includes a Lane Keeping Assistance System (LKAS) configured to sense a lane to control the vehicle to travel along the lane, and to operate a steering system regardless the driver's operation to keep the lane when lane departure is concerned.
In addition, there is a Lane Departure Warning System (LDWS) configured to sense a lane and the current position of the vehicle and to then warn of a lane departure state when the vehicle departs from a predetermined range adjacent to the lane.
Of course, the above mentioned LKAS and LDWS may be integrated with each other so as to implement a single system, and in such an integrated lane control system may include both of a function of making a warning when there is the possibility of a lane departure and a function of actively controlling the steering systems to keep the lane.
When a system having the lane departure warning device is used, too many lane departure warnings may occur depending on a driver's driving habits.
In a case where the vehicle may frequently come closer to a lane (e.g., a case where the driver intentionally changes lanes in practice, or a case where the driver is a beginning driver so that it is difficult to travel in the center of the traveling way), a lane departure warning is generated whenever the vehicle comes close to the lane, which may disturb driving.
In consideration of this point, in the past, there has been proposed a technology of not generating a lane departure warning when it is possible to keep the lane by a lane keeping system even if the vehicle enters a lane departure warning occurrence area, when the driver's lane change intention is securely confirmed, and so on.
Even in a special situation, such as a joining road or a branch road, it may be necessary to limit the lane departure warning, but no technology has been proposed for this problem.